There are two general distributor ignition systems used on the Sidekick, Tracker, Samurai and X-90 models. The earlier system is a conventional breakerless distributor ignition system and is used by 1.5L carbureted engines only. The second system, which is controlled by the Electronic Control Module (ECM) to fine-tune the ignition timing for optimal engine performance, is used on 1.5L and 1.6L engines equipped with either Throttle-body Fuel Injection (TFI) or Multi-point Fuel Injection (MFI).
The Sidekick Sport utilizes a distributorless ignition system, which is presented later in this section.
See Figures 1, 2 and 3
The principal components of this simple, yet effective, breakerless ignition system are the spark plugs, the ignition coil and the distributor, which is composed of a rotor, an igniter, a signal generator, a vacuum advance mechanism and a centrifugal advance mechanism.
The signal generator, which manufactures the ignition reference signal, is composed of a signal rotor, a magnet and a pick-up coil. The signal rotor reference signal turns the igniter on and off, which, in turn, switches the ignition coil primary current off, thereby inducing a high voltage current in the secondary windings of the ignition coil. This high voltage current is then routed to the applicable spark plug.
Through the use of mechanical (centrifugal) and vacuum advance mechanisms, the ignition spark timing is automatically advanced or retarded as needed for optimum engine performance.
TFI & MFI ENGINES
See Figures 4, 5 and 6
Disconnecting the battery cable on some vehicles may interfere with the functions of the on board computer systems and may require the computer to undergo a relearning process, once the negative battery cable is reconnected.
The ignition system used by vehicles equipped with TFI or MFI fuel delivery systems utilizes an Ignition Control (IC) system. The IC system is referred to as the Electronic Spark Advance (ESA) system on 1989-95 models. The IC system is comprised of the following components:
The IC system is controlled by the ECM, which is programmed to provide the most advantageous ignition timing under every engine condition. The ECM receives incoming reference signals from various sensors and switches which convey the current engine condition (such as engine speed, intake air volume, coolant temperature, crankshaft position, etc.). The ECM uses the incoming information to select the most appropriate ignition timing from its memory, and adjusts the ignition timing by exact operation of the igniter.
The ECM reference signal turns the igniter on and off, which, in turn, switches the ignition coil primary current off, thereby inducing a high voltage current in the secondary windings of the ignition coil. This high voltage current is then routed, via the distributor, to the applicable spark plug.